Damping-off Damping-off disease is a worldwide problem. It occurs in most soils including temperate and tropical as well as in greenhouses. Damping-off refers to the sudden plant death in the seedling stage and results from attack by fungi or other extremes in the soil.
Damping-off kills or damages the seeds and seedlings of many plants. The extent of damage is dependent on the type of fungus, soil moisture and temperature. The most favorable environment for damping-off is cool wet soils.
Although it is usually seeds and seedlings that are attacked, damping-off disease can also attack older established plants. Usually the new developing rootlets are infected, resulting in root rot. Infected plants show symptoms of wilting and poor growth. Controlling damping-off: Proper conditions for seed germination and seedling emergence also favor vigorous growth of fungi that cause damping-off. Seed and roots must be kept moist and warm until the roots have penetrated the soil and the seedlings have emerged. As the seedlings continue to grow, moisture at the soil surface can be decreased, and the damping-off fungi then will have less of an advantage. Additionally:
1- keep the fungi that cause it out of the flats of seeds. 2- Encourage the seeds to germinate and grow as fast as possible. Plants are only susceptible to damping-off as seedlings. 3- Help prevent this disease from causing huge losses (although some loss may occur) is to keep conditions in the seeding trays less favorable to the fungi. These fungi like wet conditions.
* Use well-drained planting media. * Sow seeds thinly to allow air to circulate between seedlings. * Avoid excessive watering.
In addition to these measures, use fungicide treated seeds, and see current recommendations for chemical control measures. As always, contact a local County Extension Agent or Master Gardener for recommendations. They are familiar with your specific region and types of damping-off problems and solutions. |